This invention relates to a mechanism to move rigid flat material through a cutter so that the material remains in constant orientation to the cutter as it passes through the cutter and, more particularly, to a mechanism to move wooden boards containing defects through trimmer saws to yield useable boards.
It is known that boards with defects or wanes can be optically scanned and the largest piece of useable wood cut therefrom by computer analysis. See S. J. Oppeneer, U.S. Pat. No. 4,794,963 and J. M. Idelsohn, U.S. Pat. No. 4,207,472. The previous attempts to accomplish the goals of this invention have utilized standard rollers to move the boards past the cutting saws plus hold-down rollers from above and a fence along one side. See U. Moilanen, U.S. Pat. No. 4,485,705 and E. G. Fornell, U.S. Pat. No. 4,269,245. The way the prior art attempts to maintain constant orientation of the boards to the trimming saws is by means of gripping clamps which damage the wood being trimmed. See A. U. Jones, U.S. Pat. No. 5,088,363 and G. W. Head Jr., U.S. Pat. No. 5,381,712.
Another known means for transporting the material to the cutter is a slat-bed transport device, which consists of multiple parallel chains on which cross “slats” are affixed at regular intervals along a continuous loop of traveling chain. The chains usually ride in a track and there are ‘V’ block attachments on the underside of the cross slats which ride upon a ‘V’ guide. This means of transporting material to a cutter has many complex parts which are more expensive to manufacture and to maintain than this invention and require regular lubrication, which lubricant can transfer to the material being transported and stain it. The metal slats do not maintain the alignment of the material with the cutter unless they are equipped with spikes or a rough surface which mars the material to be cut just as do the gripping clamps of referred to above.
The primary object of this invention is to provide a device to maintain the precise orientation of a board to cutting or shaping mechanisms and to move the board through the cutting or shaping mechanisms at a constant rate without marring the surface of the wood.